Acne Scars

J Neurosci. 2009 May 20; 29(20): 6722-33Sellers DL, Maris DO, Horner PJProgenitors that express NG2-proteoglycan are the predominant self-renewing cells within the CNS. NG2 progenitors replenish oligodendrocyte populations within the intact stem cell niche, and cycling NG2 cells are among the first cells to react to CNS insults. We investigated the role of NG2 progenitors after spinal cord injury and how bone morphogen protein signals remodel the progressive postinjury (PI) niche. Progeny labeled by an NG2-specific reporter virus undergo a coordinated shift in differentiation profile. NG2 progeny born 24 h PI produce scar-forming astrocytes and transient populations of novel phagocytic astrocytes shown to contain denatured myelin within cathepsin-D-labeled endosomes, but NG2 progenitors born 7 d PI differentiate into oligodendrocytes and express myelin on processes that wrap axons. Analysis of spinal cord mRNA shows a temporal shift in the niche transcriptome of ligands that affect PI remodeling and direct progenitor differentiation. We conclude that NG2 progeny are diverse lineages that obey progressive cues after trauma to replenish the injured niche.

Ann Plast Surg. 2009 Jun; 62(6): 660-4Ogawa R, Akaishi S, Hyakusoku HPrevious articles suggested the presence of various kinds of malignant tumors that resemble keloid or hypertrophic scar, including dermatofibrosarcoma protuberans, trichilemmal carcinoma, and keloidal basal cell carcinoma. Thus, we studied our cases that were diagnosed with diseases other than keloid or hypertrophic scar. From April 2003 to March 2007, we examined 378 patients self diagnosed with keloid or hypertrophic scar.We detected 4 other diseases (1.06%) in the group of patients. All tumors were benign: apocrine cystadenoma, adult-onset juvenile xanthogranuloma, mixed tumor, and chronic folliculitis. Our study led us to the conclusion that differential or exclusive diagnosis of diseases similar to keloid and hypertrophic scar is important. We found the following considerations important in the examination of keloid or hypertrophic scar: (1) biopsy should be conducted in anomalous cases because malignant disease may be the original or secondary problem, (2) steroid injection should be performed only after careful consideration because malignancy or infections may be present, (3) careful differential diagnosis is particularly challenging in African-Americans because skin and tumor color are often similar, and (4) the presence of bacterial or fungal infection should be investigated.